Herpesvirus type 11 was recovered from approximately 16 per cent (8/51) of pregnant women currently in a longitudinal study. No systemic virus could be recovered from peripheral lymphocytes even during acute phase using direct rescue or mitogenic activation techniques. Delayed hypersensitivity to Herpesvirus type 11 virions was demonstrated in 6/8 cases where virus was recovered while two cases of active virus shedding failed to show a cell-mediated response.